Hi,
I am working on a parallel port code, in which I want to achieve the
interrupt on pin 10. I have created a sample circuit as mentioned in
Book LDD. I have connected pin 9 to pin 10 and writing 0x00 and 0xFF
on the port to generate interrupt.
I have created one sample code.
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[Code]
#include<linux/init.h>
#include<linux/module.h>
#include<linux/fs.h>
#include<linux/cdev.h>
#include<linux/slab.h>
#include<linux/io.h>
#include<linux/ioport.h>
#include<linux/interrupt.h>
#include<asm/uaccess.h>
#include<asm/irq.h>
#include "parportD.h"
MODULE_LICENSE("Dual BSD/GPL");
int parportD_minor, parportD_major, parportD_count;
struct cdev *parportD_cdev;
dev_t dev = 0;
int flag;
int intID = 3;
int s = 0;
struct resource *res;
unsigned long portID = 0x378;
unsigned long length = 0x08;
struct file_operations cDevice_fops = {
.owner = THIS_MODULE,
.read = parportD_read,
.write = parportD_write,
.open = parportD_open,
.release = parportD_release,
};
irqreturn_t intHandle(int irq, void *dev_id)
{
printk("Interrupt occured.");
s = 1;
outb_p(0x00, portID + 2);
outb_p(0x10, portID + 2);
return IRQ_HANDLED;
}
static int parportD_init(void) {
int retVal, err;
printk("parportD initialization started.\n");
parportD_count = 0x01;
parportD_minor = 0x00;
/* res = request_region(portID, length ,"parportD");
if (res == NULL) {
printk(KERN_NOTICE "Port allocation failed.");
return -1;
}*/
retVal = alloc_chrdev_region(&dev, parportD_minor, 1, "parportD");
if (retVal != 0x00) {
printk(KERN_NOTICE "chrdev region allocation failed.");
return -1;
}
parportD_major = MAJOR(dev);
parportD_minor = MINOR(dev);
printk("retVal = %d\n", retVal);
printk("Major number = %d\n", parportD_major);
printk("Minor number = %d\n", parportD_minor);
printk("Device count = %d\n", parportD_count);
parportD_cdev = cdev_alloc();
cdev_init(parportD_cdev, &cDevice_fops);
parportD_cdev->owner = THIS_MODULE;
err = cdev_add(parportD_cdev, dev, 1);
if (err < 0) {
printk(KERN_NOTICE "Error %d adding parportD", err);
} else {
printk("parportD initialization completed.\n");
}
//request IRQ
retVal = request_irq(intID, intHandle, IRQF_DISABLED, "parportD", NULL);
printk("Interrupt request return value = %d\n", retVal);
if (retVal ) {
printk("Interrupt request failed. = %d\n", retVal);
} else {
//enable intrrupts
outb(0x10, portID+2);
printk("Interrupt enabled.\n");
}
return 0;
}
static void parportD_exit(void) {
printk("parportD exit started.\n");
cdev_del(parportD_cdev);
free_irq(intID, NULL);
release_region(0x378, 8);
printk("parportD exit completed.\n");
}
int parportD_open(struct inode *inode, struct file *filep) {
int retVal = 0x00;
printk("parportD opend.\n");
return retVal;
}
int parportD_release(struct inode *inode, struct file *filep) {
printk("\nparportD released.\n");
return 0x00;
}
ssize_t parportD_read(struct file *filep, char *buf, size_t count,
loff_t *f_pos) {
/*ssize_t retVal = 0x00;
printk("Device read received.\n");
retVal = copy_to_user((void *)buf, (void*)data, count);
printk("Device read = %s ratVal = %d count = %d \n", buf,
retVal, count);*/
return count;
}
ssize_t parportD_write(struct file *filep, const char *buf, size_t
count, loff_t *f_pos) {
printk("Device write received.\n");
printk("s = %d\n", s);
if(flag == 0) {
flag = 1;
outb(0, portID);
printk("Wrote 0 on port. \n");
} else {
flag = 0;
outb(255, portID);
printk("Wrote 255 on port. \n");
}
printk("Data received = %s", buf);
return count;
}
module_init(parportD_init);
module_exit(parportD_exit);
[/Code]
##------------------------------------------------------------------------------------------------------------------------------
Problem here is, I am not getting interrupt or my interrupt handler is
not executing. I wonder do we need to do any setting in BIOS for this
interrupt? Or do we need to enable any flag during kernel compilation?
Vishal N
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